About this Article
Written by: Meena Singh
Written on: November 1st, 2001
Tags: biomedical engineering, health & medicine, lifestyle
Thumbnail by: Food and Drug Administration/Wikimedia Commons
About the Author
At the time of writing, Meena Singh was a junior pre-medical student majoring in Biomedical (Biochemical) Engineering. She plans to earn her B.S. degree in May 2003.
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Volume II Issue IV > The Design and Use of Soybean Oil-Filled Breast Implants in Augmentation Mammioplasty
Many women who are unsatisfied with the appearance of their breasts use augmentation mammioplasty, or breast augmentation, to achieve their desired look. The most commonly used breast implants are silicone gel and saline-filled implants, both of which have harmful drawbacks. Silicone gel are not biocompatible and obstruct the visibility of tumors in mammography. Saline-filled implants are found to harbor microbes that can cause infection. Because of these disadvantages, scientists have investigated the use of safer, natural alternatives to implant filler materials. The Trilucent soybean oil-filled breast implant was designed for increased safety, longer life, and radiolucency (ability to visualize tumors on a mammogram). These implants were thought to have additional advantages, such as increased biocompatibility and prevention of microbe growth. Additionally, the implant has a valve that allows surgeons to adjust its size after implantation and a microchip that allows doctors to track implant information. The Trilucent breast implant was supposedly the best implant design thus far; however, unpredicted complications arose in patients, causing the Trilucent implant to be removed from the market.

The Need for Breast Augmentation

Breast augmentation is the second most commonly performed cosmetic surgery in the United States [1]. Women who undergo this procedure typically want to enhance their body contour to increase their bust size, balance breasts that are different in size, or correct a reduction in breast volume after pregnancy. Over the past 30 years, nearly two million women have received breast implants in North America [2]. In recent years, breast implants have been in particularly high demand [1].

Background of Breast Implants

Food and Drug Administration/Wikim​edia Commons
Figure 1: Silicone breast implant.
The optimal breast implant should be nontoxic, noncarcinogenic (non cancer-causing), sterilizable, biocompatible, radiolucent (able to visualize tumors in a mammogram) and relatively affordable [3]). Since the introduction of breast prosthesis in 1962, silicone gel-filled implants (see Fig. 1) have been the dominant implants; yet they are neither biocompatible nor radiolucent [3]. Saline-filled implants are also radiopaque on mammograms, making it difficult to recognize tumors [3]. Additionally, breast implants can eventually rupture, releasing a few cupfuls of fluid into the breast tissue. In saline-filled implants, this fluid might harbor a wide variety of potentially harmful microbes. These microbes can infect the tissue surrounding these implants, squeezing the area around the implant, and causing the breasts to harden and contract [4].

Soybean Oil-Filled Breast Implants

Because of the unsafe drawbacks of silicone gel and saline-filled implants, scientists have investigated safer, natural alternatives for filler materials. In the 1980's, scientists at Washington University developed the Trilucent soybean oil-filled breast implant (Lipomatrix, Neuchatel, Switzerland). It was implanted in about 10,000 European women in 1994 and 1995 [5]. The soybean oil-filled breast implant functions like a saline-inflatable implant, but was engineered for radiolucency, safety, and longer life.

Properties of the Filler Material

The Trilucent breast implant is filled with Trilipid Z6, which contains highly refined medical-grade triglyceride fats extracted from soybean oil [6]. A triglyceride is a macromolecule (complex molecule composed of smaller molecules) containing three long fatty acid chains bound to a molecule of glycerol. The triglycerides in Trilipid Z6 are composed of 60% polyunsaturated fatty acids, 26% monounsaturated fatty acids, and 14% saturated fatty acids [5].